Integrated circuit devices currently are being manufactured with a large number of pins, which include input/output pins, pins to be connected to one or more supply voltages (VDD), and pins which are to be connected to ground in the operation of the device. Sixty-four pin integrated circuit devices are common; and large scale integrated circuits, including up to five-hundred twelve pins, currently exist.
In the manufacture of integrated circuit devices, and, in many cases, prior to the inclusion of such integrated circuit devices into equipment incorporating these devices, it is desirable to test the operating characteristics of the devices. This typically is done by a multiple channel tester, which is capable of applying required power supply and ground potentials to selected pins of the integrated circuit device under test, and also for supplying signals to and receiving signals from the input/output (I/O) pins of the device under test. The integrated circuit tester equipment typically is interconnected with an integrated circuit device under test (DUT) by means of a load board, which provides the desired interface between the tester and the device to be tested.
Load boards or performance boards for testing integrated circuit devices are relatively complex and expensive. Frequently, load boards are custom designed to provide a specific interface between a particular integrated circuit device which is to be tested and the tester, which is used to operate the device during its test mode of operation. If a tester is always used to test the same integrated circuit devices, a dedicated load board for interfacing between the tester and the integrated circuit device is practical. If a different integrated circuit device, however, having the same number of pins, but arranged in a different order, or devices having different numbers of pins are to be tested, it has been necessary to have a different specific dedicated load board for each different integrated circuit device. This is quite expensive.
Universal load boards have been designed which are capable of interfacing different integrated circuit devices undergoing test with a tester system. When a universal load board is used, the board must have the capacity to set any of the interface channels to match any of the channels of the tester to any one of the pins on the integrated circuit device undergoing test to operate either as an input/output pin, or to be connected to ground or to a source of power (VDD). This is accomplished by providing separate power supply attribute relays on the universal load board or performance board for each of the channels. Manually set toggle switches then have been used as memory devices for activating selected ones of the relays, in accordance with the desired interconnections which are to be effected between the tester to the integrated circuit device under test. The time required for setting each of these toggle switches is considerable. It also is necessary carefully to check the switch settings prior to operation of the tester to ensure that no errors exist, which then would invalidate the subsequent tests to be run. Substantial potential for error exists in such a system.
Consequently, it is desirable to provide an improved system for setting the power supply attribute relays of a universal performance board used in conjunction with an integrated circuit tester.